vga_bitblt(3) Svgalib User Manual vga_bitblt(3)NAMEvga_bitblt - copy pixmap on screen using an accelerator
SYNOPSIS
#include <vga.h>
void vga_bitblt(int srcaddr, int destaddr, int w, int h, int pitch);
DESCRIPTION
Bitblit (copy rectangular area in video memory), addresses are offsets
into video memory (up to 2M). The pitch is the logical width of the
screen. Height h is in Pixels, Width w is in BYTES!
This is an old style function to access the accelerator of an SVGA
card. Before calling it you should check for availability of the func‐
tion in the mode you use with vga_getmodeinfo(3).
For new applications you might be better of trying to use vga_accel(3)
instead.
The old vga_bitblt(3), vga_blitwait(3), vga_fillblt(3), vga_hlinelist‐
blt(3), and vga_imageblt(3) interface was originally designed for the
Cirrus chipsets. Then Mach32 added support too but has problems to
resemble the unintuitive Cirrus interface. Then these new ideas were
reinjected and vga_accel(3) was designed. Now Cirrus and Chips & Tech‐
nologies chipset give limited vga_accel(3) support but no longer this
old style support. Mach32 is left to use the unintuitive Cirrus inter‐
face. At some future point the functions might be added for Mach32 too
(which should be rather simple), so new applications should use the
newer and probably more efficient interface.
It would be fatal if the accelerator would be used while the console is
switched away. You should use vga_lockvc(3) and vga_unlockvc(3) to
avoid this, although good implementations of the accelerator functions
(like Mach32) will already ensure that.
The testaccel(6) demo utilizes the old style accelerator functions.
SEE ALSOsvgalib(7), vgagl(7), libvga.config(5), testaccel(6), vga_accel(3),
vga_blitwait(3), vga_fillblt(3), vga_hlinelistblt(3), vga_imageblt(3),
vga_getmodeinfo(3), vga_lockvc(3), vga_unlockvc(3)AUTHOR
This manual page was edited by Michael Weller <eowmob@exp-math.uni-
essen.de>. The exact source of the referenced function as well as of
the original documentation is unknown.
It is very likely that both are at least to some extent are due to Harm
Hanemaayer <H.Hanemaayer@inter.nl.net>.
Occasionally this might be wrong. I hereby asked to be excused by the
original author and will happily accept any additions or corrections to
this first version of the svgalib manual.
Svgalib (>= 1.2.11) 27 July 1997 vga_bitblt(3)
